Content playback apparatus, content playback method and storage medium

ABSTRACT

A content playback apparatus includes: a display section that displays a plurality of indicators associated with a plurality of pieces of content, and a specifier to be used to specify one of the indicators; a playback section that plays back the piece of content associated with the indicator specified by the specifier; a switch section that switches, in accordance with a user&#39;s operation, what the specifier specifies to new the indicator; and a playback control section that controls the playback section such that if the user&#39;s operation switches, while the piece of content associated with the indicator specified by the specifier is played, what the specifier specifies to next the indicator and the user&#39;s subsequent operation switches, within a predetermined period of time from when the previous switch is completed, what the specifier specifies to subsequent the indicator, the playback section keeps playing back the piece of content.

CROSS REFERENCES TO RELATED APPLICATIONS

The present invention is a continuation of U.S. Ser. No. 11/654,730,filed Jan. 18, 2007, which claims the priority benefit of Japanesepatent application number 2006-014214, filed in the Japanese PatentOffice on Jan. 23, 2006, which is hereby incorporated by reference tothe maximum extent allowable by law.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a content playback apparatus, contentplayback method and storage medium for storing a content playbackprogram, and is preferably applied to a case in which a user interfaceis provided to retrieve the user's desired piece of music content out ofmany pieces of music content, for example.

2. Description of Related Art

In recent years, a content playback device is here to stay: the contentplayback device stores many pieces of digital content, such as music andvideo, in a large-capacity hard disk and the like; the content playbackdevice is also capable of acquiring the digital content from externalservers through a high-speed network and the like; the content playbackdevice plays back the piece of digital content specified by a user.

For example, Jpn. Pat. Laid-open Publication No. 2004-356774 discloses acontent playback device which displays rows of thumbnails each of whichis associated with each piece of content after classifying them bycontent (media) type. This allows a user to easily select pieces ofcontent.

SUMMARY OF THE INVENTION

By the way, there is a content playback device, which stores many piecesof music content, capable of immediately playback the piece of musiccontent selected through a cursor by a user for trial listening. Thishelps the user to realize what the pieces of music content are whenhe/she selects one to play back.

In a case in which the user continuously selects the pieces of musiccontent to find out his/her desired one, they are played back one afteranother for a short period of time.

In this case, the content playback device repeatedly changes what itplays back for a short period of time. This may sound like nose to theuser who may then feel uncomfortable.

The present invention has been made in view of the above points and isintended to provide a content playback apparatus, content playbackmethod and storage medium for storing a content playback program thatcan change the piece of content without discomfort.

In one aspect of the present invention, a content playback apparatusperforms the process of: displaying a plurality of indicators associatedwith a plurality of pieces of content, and a specifier to be used tospecify one of the indicators; playing back the piece of contentassociated with the indicator specified by the specifier; switching, inaccordance with a user's operation, what the specifier specifies to newthe indicator; and controlling such that if the user's operationswitches, while the piece of content associated with the indicatorspecified by the specifier is played, what the specifier specifies tonext the indicator and the user's subsequent operation switches, withina predetermined period of time from when the previous switch iscompleted, what the specifier specifies to subsequent the indicator, thepiece of content keeps being played.

Accordingly, the user's operation that continuously switches what thespecifier specifies does not switch the piece of content to be playedone after another for a short period of time. Instead, that keepsplaying back the originally-specified piece of content.

According to an embodiment of the present invention, the user'soperation that continuously switches what the specifier specifies doesnot switch the piece of content to be played one after another for ashort period of time. Instead, that keeps playing back theoriginally-specified piece of content. Thus, the content playbackapparatus, content playback method and storage medium for storing acontent playback program can change the piece of content withoutdiscomfort.

The nature, principle and utility of the invention will become moreapparent from the following detailed description when read inconjunction with the accompanying drawings in which like parts aredesignate by like reference numerals or characters.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a schematic perspective view of an audio device;

FIG. 2 is a schematic block diagram illustrating the circuitconfiguration of the audio device;

FIG. 3 is a schematic block diagram illustrating the functionalconfiguration of the audio device;

FIGS. 4A and 4B are schematic diagrams illustrating the configuration ofa data management table;

FIG. 5 is a schematic diagram illustrating the information displayed ona front panel in all music display mode;

FIG. 6 is a schematic diagram illustrating the configuration of a focusframe;

FIG. 7 is a schematic diagram illustrating methods of selecting anddisplaying the pieces of music content;

FIGS. 8A and 8B are schematic diagrams illustrating selection of contentand timing of reproduction;

FIGS. 9A to 9G are schematic diagrams illustrating playback of contentin low speed switch mode;

FIGS. 10A to 10E are schematic diagrams illustrating playback of contentin high speed switch mode;

FIG. 11 is a flowchart illustrating a procedure of selection contentswitch process;

FIG. 12 is a flowchart illustrating a procedure of selection contentplayback process;

FIG. 13 is a schematic diagram illustrating thumbnail images scrolled;

FIGS. 14A and 14B are schematic diagrams illustrating playback volumelevels during a process of switching the pieces of content;

FIGS. 15A and 15B are schematic diagrams illustrating volume levels andsound localization at time instance t31;

FIGS. 16A and 16B are schematic diagrams illustrating volume levels andsound localization at time instance t32;

FIGS. 17A and 17B are schematic diagrams illustrating volume levels andsound localization at time instance t34;

FIGS. 18A and 18B are schematic diagrams illustrating volume levels andsound localization at time instance t36; and

FIGS. 19A and 19B are schematic diagrams illustrating volume levels andsound localization at time instance t37.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

An embodiment of the present invention will be described in detail withreference to the accompanying drawings.

(1) Overall Configuration of Audio Device

In FIG. 1, the reference numeral 1 denotes an audio device according toan embodiment of the present invention. An insertion slot 3 is placed ona right side panel 2A of a housing 2. The insertion slot 3 accepts anoptical disc 4 such as Digital Versatile Disc (DVD) and Compact Disc(CD). An entry slot 5 is placed below the insertion slot 3. The entryslot 5 accepts a small memory card 6 such as “MEMORY STICK (RegisteredTrademark of Sony Corporation)”.

The audio device 1 also includes the following components: a contentdisplay section 8, such as liquid crystal display, on a front panel 7;an operation button disposed area 10 on the right of the content displaysection 8; and a zoom dial 12 with a selection dial 11 on the bottomright of the content display section 8 and the operation button disposedarea 10. The zoom dial 12, which is larger than the selection dial 11,is placed under the selection dial 11 that is to be used to select apiece of music content.

In addition, the audio device 1 includes time axis bar display sectionsTB1 and TB2 (described below) to present pieces of music content inchronologic order, or in order of time. The time axis bar displaysections TB1 and TB2 are for example equivalent to a liquid crystaldisplay, being placed below the content display section 8 and theoperation button disposed area 10.

The audio device 1 is capable of playing back the piece of music contentfrom the optical disc 4 in the insertion slot 3 and from the smallmemory card 6 in the entry slot 5 to output music through a speaker (notshown) connected to the audio device 1. In addition, the audio device 1is capable of reading out the pieces of music content from the opticaldisc 4 and the small memory card 6 to store them in an internal HardDisk Drive.

Furthermore, the audio device 1 is capable of connecting to the Internetthrough a network cable. This allows the audio device 1 to download thedesired piece of music content from external servers on the Internet andthen store it in the internal Hard Disk Drive.

The operation button disposed area 10 includes a group of operationbuttons 9: a playback button 9A, which is to be used to play back orstop the piece of music data selected by the selection dial 11; a skipbutton 9B, which is used to skip the piece of music content; a volumecontrol button 9C; a recording button 9D; a timer setting button 9E; auser rating button 9F; a menu button 9G, which is used to switch modes;optional buttons 9H to 9K, to which various functions may be assignedaccording to the modes; and a cancel button 9L. The audio device 1performs various processes in accordance with the user's operation ofthe operation buttons 9.

(2) Internal Configuration of Audio Device

(2-1) Circuit Configuration

As shown in FIG. 2, a control section 20 takes overall control of theaudio device 1. In the control section 20, a Central Processing Unit(CPU) 20A reads out programs, such as basic programs and content displayprograms, from a Read Only Memory (ROM) 20B through a bus 21, and thenloads them onto a Random Access Memory (RAM) 20C to perform processessuch as a content display process.

The control section 20 for example rips music data from the optical disc4 (FIG. 1) that has been inserted into a DVD drive 23 through theinsertion slot 3 (FIG. 1). The control section 20 then encodes the musicdata in the format of MPEG-1 Audio Layer 3 (MP3), Adaptive TransformAcoustic Coding 3 (ATRAC3) or the like to generate the piece of musiccontent MC. Alternatively, the control section 20 directly reads out thepiece of music content MC, which has been already encoded, from thesmall memory card 6 that has been inserted into a memory card drive 24through the entry slot 5 (FIG. 1). The control section 20 stores thepiece of music content MC in a Hard Disk Drive (HDD) 22.

The control section 20 also acquires the music content MC from anexternal content server (not shown) through a network interface 25, andthen stores it in the Hard Disk Drive 22.

In addition to that, the control section 20 acquires, from the externalcontent server and other servers that are connected to the audio device1 through the Internet, a thumbnail image SG including a jacketphotograph of the piece of music content MC, and metadata MTD includingmusic names, artist names, and release date of the piece of musiccontent MC. The control section 20 subsequently reduces the size of thethumbnail image SG in all directions, and then compresses the size ofthumbnail image SG in horizontal direction to produce a content icon CA.The control section 20 then stores the content icon CA in the Hard DiskDrive 22 such that it is associated with the piece of music content MC.

By the way, the Hard Disk Drive 22 has enough space to store, forexample, thousands to tens of thousands of pieces of music content MC.

A video controller 26A of a display section 26 obtains a display commandfrom the control section 20 via the bus 21. In response to the displaycommand, the video controller 26A displays a plurality of thumbnailimages SG of the pieces of music content MC on the content displaysection 8 of the front panel 7. In addition, the video controller 26Adisplays the content icon CA on the time axis bar display sections TB1and TB2, and also updates, in response to the display command, thedisplayed information.

When a user rotates the selection dial 11 to the right or left (thisoperation will be also referred to as “selection operation”), a rotaryencoder (not shown) of an operation input section 27 in the selectiondial 11 generates, in response to the rotated angle (the amount ofrotation), a rotation signal SR1, and then supplies the rotation signalSR1 to the control section 20 through an input interface 27A and the bus21.

In response to that, the control section 20 switches what it focuses toa right- or left-hand thumbnail image SG on the content display section8. In this manner, the control section 20 changes what it selects fromone piece of music content MC to another (described later in detail).

When a user rotates the zoom dial 12 to the right or left (thisoperation will be also referred to as “zoom change operation”), a rotaryencoder (not shown) of the operation input section 27 in the zoom dial12 generates, in response to the rotated angle (the amount of rotation),a rotation signal SR2, and then supplies the rotation signal SR2 to thecontrol section 20 through the input interface 27A and the bus 21.

In response to that, the control section 20 changes an extractioncondition that defines which thumbnail images SG the content displaysection 8 displays out of the thumbnail images SG of all pieces of themusic content MC stored in the Hard Disk Drive 22, and updates thethumbnail images SG on the content display section 8. The controlsection 20 also updates a display pattern of the content icons CA on thetime axis bar display sections TB1 and TB2 (described later in detail).

When the operation buttons 9 are pushed, the operation input section 27generates a push signal SU, and then supplies the push signal SU to thecontrol section 20 through the input interface 27A and the bus 21. Inthis case, the control section 20 performs various processes in responseto the operation button pushed (i.e. the playback button 9A to thecancel button 9L), such as playback process.

When the playback button 9A of the operation buttons 9 is pushed whileany piece of music content MC is not being played back, the controlsection 20 reads out the piece of music content MC, which is associatedwith the focused (or selected) thumbnail image SG, from the Hard DiskDrive 22, and then supplies the piece of music content MC to an audiocontroller 29 of an audio reproduction section 28 via the bus 21.

The audio controller 29 receives the piece of music content MC, whichwas read from the Hard Disk Drive 22, via the bus 21, and then performsprocesses in accordance with the encoding format of the music contentMC, such as decoding and Digital-to-Analog (D/A) conversion, to producea reproduced signal SA. The audio controller 29 subsequently amplifiesthe reproduced signal SA by an amplifier 30, and then supplies it to aspeaker 31 which then outputs, based on the reproduced signal, sound.

The control section 20 acquires time information from a clock circuit 32through the bus 21 to obtain the current time. The control section 20repeatedly acquires the current times and calculates the differencesbetween them. In this manner, the control section 20 calculates elapsedtime between two points in time.

In this manner, the audio device 1 displays the thumbnail image SG ofthe piece of music content MC stored in the Hard Disk Drive 22 on thecontent display section 8 and the like, and also updates the informationdisplayed on the content display section 8 and the like in response tothe selection operation or zoom change operation of the operation inputsection 27 about the pieces of music content MC, and then plays back theselected piece of music content MC.

(2-2) Functional Configuration

FIG. 3 shows the functional configuration of the audio device 1,detailing the functions of displaying the thumbnail images SG.

The Hard Disk Drive 22 stores the following data in a content storagesection 22A: the pieces of music content MC, and the thumbnail images SGand content icons CA corresponding to the pieces of music content MC.The Hard Disk Drive 22 also stores various metadata MTD, such as musicnames, artist names, release data and annual ranking of the pieces ofmusic content MC, in a content metadata storage section 22B.

The Hard Disk Drive 22 uses a content data management table TBL1 (FIG.4A) to manage the pieces of music content MC, which are stored in thecontent storage section 22A, their thumbnail images SG and content iconsCA as a file with a predetermined content name indicated by a contentID. FIG. 4B shows a content metadata management table TBL2 that managesvarious metadata MTD, which are stored in the content metadata storagesection 22B, as a file with a content metadata name indicated by acontent ID.

When a user performs the selection operation through the selection dial11 of the operation input section 27 to select a piece of music contentMC, a reproduction control section 20D of the control section 20acquires the metadata MTD of the selected piece of music content MC fromthe content metadata storage section 22B of the Hard Disk Drive 22through a content metadata management section 20F. The reproductioncontrol section 20D of the control section 20 also reads out a file (thepiece of music content MC) specified by the metadata MTD from thecontent strage section 22A of the Hard Disk Drive 22 through a contentmanagement section 20E, and then supplies the file to the audioreproduction section 28.

In response to that, the audio reproduction section 28 performsprocesses, such as decoding process and amplification process on thepiece of music content MC, to reproduce sound of the piece of musiccontent MC, and then allows the user to listen to it.

In addition, when the user performs the selection operation through theselection dial 11 of the operation input section 27 to switch the pieceof music content MC, the reproduction control section 20D of the controlsection 20 updates the thumbnail images SG displayed on the contentdisplay section 8 of the display section 26. In addition, in accordancewith the selection operation, the reproduction control section 20D keepsplaying the currently played piece of music content MC, or switches whatit plays back to the recently selected piece of music content MC(described below in detail).

(3) Configuration of Front Panel

The audio device 1 according to an embodiment of the present inventionhas enough space to store thousands to tens of thousands of pieces ofmusic content MC in its internal Hard Disk Drive 22. The front panel 7is designed to allow a user to easily retrieve his/her desired piece ofmusic content MC from many pieces of music content MC without usingmusic or artist names.

(3-1) All Music Display Mode

As shown in FIG. 5, the front panel 7 of the audio device 1 includes thefollowing components: the content display section 8, which displays aplurality of pieces of thumbnail images SG (5 pieces, in this case) eachof which includes a jacket photograph and the like of the music content(the thumbnail image SG is for example equivalent to an indicator); thetime axis bar display section TB1, where the content icons CA1 to CAncorresponding to all pieces of music content MC stored in the Hard DiskDrive 22 are displayed side by side in order of release date (year,month and day of release); and the time axis bar display section TB2,where the content icons CA of the pieces of music content MC that havebeen culled in a predetermined manner at the time of content retrievalas low-priority data are displayed side by side in order of release date(year, month and day of release).

An all music display mode displays all the content icons CA1 to CAn onthe time axis bar display section TB1 in order of release date (year,month and day of release), and does not display any content icons CA onthe time axis bar display section TB2.

If the user selects one piece of music content MC by the selection dial11, then this piece of music content MC is focused by the contentdisplay section 8. The content display section 8 visually notifies theuser of the fact that the piece of music content MC has been focused byfor example putting a red focus frame FC1 (equivalent to a specifier) onthe thumbnail image SG of this piece of music content MC. In addition,the content display section 8 displays its release year and music name(“1981/Autumn color”, in this case) on an red underline UL1 extendingupward from the focus frame FC1, and its artist name (“YUNNZU”, in thiscase) under an red underline UL2 extending downward from the focus frameFC1.

In this manner, the audio device 1 allows the user to easily recognizethe piece of music content MC, which is currently selected by theselection dial 11 through the focus frame FC1 of the content displaysection 8, by checking the thumbnail image SG, the characters on theunderline UL1 and the characters under the underline UL2. The piece ofmusic content MC currently selected by the focus frame FC1 is alsoreferred to as a “piece of selection content SC”.

Especially, the audio device 1 can present the piece of music content MCas an image of the thumbnail image SG. Therefore the user who does notremember anything like its music and artist names but its image caneasily determine whether this piece of music content is what he/shewants to retrieve. In addition, that reminds him/her that this piece ofmusic content MC is there. Accordingly, this piece of music content MCcan be included in his/her retrieval target.

The time axis bar display section TB1 on all music display mode displaysthe content icons CA1 to CAn in order of release date (year, month andday), or in order of time. In accordance with that, the content displaysection 8 displays the character strings TX1 to TX3 indicative of therelease date of the content icon CA1 to CAn (1968, 1981, and 1990, inthis case) on the bottom area of the content display section 8.

In addition, the time axis bar display section TB1 surrounds the fivecontent icons CA, which correspond to the five thumbnail images SG onthe content display section 8, with a red focus frame FC2 for example.This allows the user to visually understand, through the focus frame FC2and the character strings TX1 to TX3 on the content display section 8,where the piece of music content MC selected by the focus frame FC1 islocated on the time line.

Especially, as shown in FIG. 6, the time axis bar display section TB1surrounds the five content icons CA, which correspond to the fivethumbnail images SG currently displayed on the content display section8, with the focus frame FC2. Inside this, the time axis bar displaysection TB1 furthermore surrounds the content icon CA, which correspondsto the thumbnail image SG that is currently selected by the focus frameFC1 (FIG. 5), with a red focus frame FC3 and also puts yellow on thewhole content icon CA to be displayed.

In this manner, the audio device 1 associates the five thumbnail imagesSG on the content display section 8 with the five content icons CAinside the focus frame FC2 of the time axis bar display section TB1.Accordingly, the user can easily and intuitively understand whichgeneration the pieces of music content MC corresponding to the fivethumbnail images SG belong to on the time axis bar display section TB1.

In addition, the audio device 1 plays back, after the thumbnail image SGis selected by the focus frame FC1, the piece of selection content SC.This allows the user to listen to the sound of the piece of selectioncontent SC.

In this manner, the audio device 1 allows the user to check thethumbnail image SG of the piece of music content MC, its release date,and its actual sound to retrieve the piece of music content MC.Accordingly, even if the user does not remember the music name andartist name, he/she can retrieve his/her desired piece of music contentMC.

(3-2) Selection and Display of Music Content

As shown in FIG. 7, the control section 20 of the audio device 1 movesthe thumbnail images SG on the content display section 8 by one frameeach time the selection dial 11 is rotated at its minimum angularincrement by the user.

At this time, in response to the rotated direction of the selection dial11, the control section 20 of the audio device 1 displays an animationwhere the thumbnail images SG on the content display section 8 areupdated by moving to the right or left. In this manner, the thumbnailimages SG are scrolled (described in detail below).

In this manner, the control section 20 of the audio device 1 changeswhat the focus frame FC1 is selecting on the content display section 8to a next thumbnail image SG. In response to that, the control section20 moves the focus frame FC2 surrounding the five content icons CA byone frame.

At this time, the control section 20 of the audio device 1 displays therelease date and music name of the piece of music content MC (i.e. thepiece of selection content SC) corresponding to the thumbnail image SGselected by the focus frame FC1 (“1980/Hello Summer Time”, in this case)on the underline UL1, and its artist name (“YAMAGAMI TATSUHIRO”, in thiscase) under the underline UL2.

By the way, when the user operates the selection dial 11 to select adifferent piece of selection content SC, the control section 20 of theaudio device 1 plays back this piece of selection content SC. Thisallows the user to listen to sound of this piece of selection content SC(described in detail below).

Accordingly, the control section 20 of the audio device 1 can outputsound of the selection content SC in response to the user's dialoperation of the selection dial 11. In this manner, the control section20 can provide the user with the sound of the piece of music content MCwhen he/she retrieves his/her desired piece of music content MC.

(4) Play a Different Piece of Music Content

The following describes how the control section 20 of the audio device 1plays back the piece of music content MC when the piece of selectioncontent SC is switched by the user's dial operation of the selectiondial 11.

For ease of explanation, the control section 20 of the audio device 1has recognized all pieces of music content MC in order of release data:a piece of content A to a piece of content Z in that order (not shown).At first, the thumbnail image SG of the piece of content A is selectedby the focus frame FC1, and the audio device 1 is playing back sound ofthe piece of content A.

(4-1) Switching a Piece of Content One Time

The following describes a case in which the control section 20 of theaudio device 1 switches what the focus frame FC1 selects from thethumbnail image SG of the piece of content A to that of the piece ofcontent B in accordance with the user's dial operation of the selectiondial 11.

As shown in FIG. 8A, at time instant t1 when the control section 20 ofthe audio device 1 accepts the user's dial operation of the selectiondial 11, the control section 20 scrolls the thumbnail images SG on thecontent display section 8 to recognize the piece of content B, insteadof the piece of content A, as a piece of selection content SC.

At this time, as shown in FIG. 8B, the control section 20 of the audiodevice 1 does not start playing the piece of content B immediately. Thecontrol section 20 keeps playing the piece of content A during a waitingtime tw from time instant t1 (this reason will be described later).

At time instant t2 after the waiting time tw has passed since the timeinstance t1, the control section 20 of the audio device 1 stops thepiece of content A and then starts playing back the piece of content B.

In this manner, when the control section 20 of the audio device 1accepts the user's dial operation of the selection dial 11, the controlsection 20 switches the piece of selection content SC. And then, afterthe waiting time tw has passed, the control section 20 starts playingthe recently selected (switched) piece of selection content SC.

(4-2) Sequentially Switching Pieces of Content at Low Speed

The following describes a case in which the control section 20 of theaudio device 1 switches the piece of selection content SC from one toanother at low speed in accordance with the user's slow dial operationof the selection dial 11: from the piece of content A to the piece ofcontent B, the piece of content C and the piece of content D in thatorder.

As shown in FIG. 9A corresponding to FIG. 8A, when the control section20 of the audio device 1 accepts the user's first dial operation of theselection dial 11 at time instance t11, the control section 20 switchesthe piece of selection content SC from the piece of content A to thepiece of content B.

As shown in FIG. 9B, at time instance t12 when a waiting time tw haspassed since the time instance t11, the control section 20 of the audiodevice 1 stops the piece of content A to start playing the piece ofcontent B.

When the control section 20 of the audio device 1 accepts the user'ssecond dial operation of the selection dial 11 at time instance 13 whena time Δt1 (which is more than the waiting time tw) has passed since thetime instance t11, the control section 20 of the audio device 1 switchesthe piece of selection content SC from the piece of content B to thepiece of content C, as shown in FIG. 9A.

At time instance t14 when the waiting time tw has passed since the timeinstance t13, the control section 20 of the audio device 1 stops thepiece of content B to start playing the piece of content C (FIG. 9B).

In a similar way, when the control section 20 of the audio device 1accepts the user's third dial operation of the selection dial 11 at timeinstance t15 when a time Δt2 (which is more than the waiting time tw)has passed since the time instance t13, the control section 20 of theaudio device 1 switches the piece of selection content SC from the pieceof content C to the piece of content D, as shown in FIG. 9A.

At time instance t16 when the waiting time tw has passed since the timeinstance t15, the control section 20 of the audio device 1 stops thepiece of content C to start playing the piece of content D (FIG. 9B).

In this manner, when the user slowly operates the selection dial 11several times at intervals of time each of which is more than thewaiting time tw, the control section 20 of the audio device 1sequentially starts playing the pieces of selection content SC so thatthey follow the selection of the thumbnail images SG by the focus frameFC1 (this will be also referred to as “low speed switch mode”).

(4-3) Sequentially Switching Pieces of Content at High Speed

The following describes a case in which the control section 20 of theaudio device 1 switches what the focus frame F1 is selecting from onethumbnail images SG to another at high speed in accordance with theuser's relatively high-speed dial operation of the selection dial 11:from the piece of content A to the piece of content B, the piece ofcontent C and the piece of content D in that order.

As shown in FIG. 10A corresponding to FIGS. 8A and 9A, when the controlsection 20 of the audio device 1 accepts the user's first dial operationof the selection dial 11 at time instance t21, the control section 20switches the piece of selection content SC from the piece of content Ato the piece of content B.

Assume that the control section 20 of the audio device 1 accepts theuser's second dial operation of the selection dial 11 at time instancet22 when only a time Δt3 (which is less than the waiting time tw) haspassed since the time instance 21 (FIG. 10A).

At this time, the control section 20 of the audio device 1 switches thepiece of selection content SC from the piece of content B to the pieceof content C. However, because the control section 20 accepts the seconddial operation at time instance t 22 which is before the waiting time twhas passed since the time instance t21, the control section 20determines that the user has no intention to listen to the piece ofcontent B because he/she is sequentially performing the dial operation.

If the control section 20 of the audio device 1 starts playing the pieceof content B, it may be played for a very short period of time less thanthe waiting time tw. This may sound like noise to the user. Accordingly,the control section 2 keeps playing the piece of content A even afterthe waiting time tw has passed since the time instance t21 (FIG. 10B).

The control section 20 of the audio device 1 subsequently accepts theuser's third dial operation of the selection dial 11 at time instancet23 when only a time Δt4 (which is less than the waiting time tw) haspassed since the time instance t22 (FIG. 10A).

At this time, the control section 20 of the audio device 1 switches thepiece of selection content SC from the piece of content C to the pieceof content D. However, because the control section 20 accepts the thirddial operation at time instance t 23 which is before the waiting time twhas passed since the time instance t22, the control section 20determines that the user is sequentially performing the dial operationand the piece of content C should not be played back just for a shortperiod of time. Accordingly, the control section 20 keeps playing thepiece of content A even after the waiting time tw has passed since thetime instance t22 (FIG. 10B).

In a case in which the control section 20 of the audio device 1 does notaccept another dial operation during the waiting time tw from the timeinstance t23 (FIG. 10A), the control section 20 determines that the userhas stopped the dial operation at time instance t24 when the waitingtime tw has passed since the time instance t23. The control section 20then starts playing the piece of content D after stopping the piece ofcontent A (FIG. 10B).

In this case where the user swiftly operates the selection dial 11 atshort intervals, the control section 20 of the audio device 1 determinesthat the user has no intention to listen to the pieces of content B andC, and that he/she wants to skip the pieces of content B and C to playback the piece of content D. Accordingly, the control section 20 doesnot play the pieces of content B and C, and then plays back the piece ofcontent D after the piece of content A.

In this manner, the user swiftly performs the dial operation of theselection dial 11 several times at intervals of time each of which isless than the waiting time tw, the control section 20 keeps playing,while the dial operation is being performed, the same piece of selectioncontent SC selected before the dial operation began, and, when the dialoperation is completed, stops this piece of selection content SC to playback the finally selected piece of selection content SC (this mode willbe also referred to as “high speed switch mode”).

By the way, the control section 20 of the audio device 1 waits for thewaiting time tw after accepting the user's dial operation of theselection dial 11. This allows the control section 20 to determinewhether the dial operation is relatively low-speed or high-speed. Basedon the result, the control section 20 determines whether to proceed tothe high speed switch mode or the low speed switch mode.

(4-4) Procedure of Selection Content Switch Process

With reference to FIG. 11, a procedure of selection content switchprocess RT1 will be described. The selection content switch process isexecuted when the control section 20 of the audio device 1 switches thepiece of selection content in response to the user's dial operation ofthe selection dial 11.

Actually, when the audio device 1 is powered on, the control section 20starts the procedure of selection content switch process RT1, and thenproceeds to step SP1. At step SP1, the control section 20 acquires timeinformation from the clock circuit 32. The control section 20 sets thetime information as an initial value of preceding rotation time to whichindicates a time instance just immediately after the dial operation isperformed, and then proceeds to next step SP2.

At step SP2, when the user performs the dial operation of the selectiondial 11, the control section 20 receives a rotation signal SR1 from theinput interface 27A of the operation input section 27, and then proceedsto next step SP3.

At step SP3, the control section 20 acquires the time information fromthe clock circuit 32, and sets the time information as current time tp.The control section 20 compares the current time tp with the precedingrotation time ta, and then proceeds to step SP4.

At step SP4, the control section 20 checks whether a difference value of(tp-ta) is greater or equal to the waiting time tw. The affirmativeresult at step SP4 means that the user has performed the dial operationrelatively slowly. This means that the control section 20 should proceedto the low speed switch mode. In this case, the control section 20proceeds to next step SP5.

At step SP5, the control section 20 scrolls the thumbnail images SG onthe display section 8 by one frame in a direction corresponding to therotation direction of the selection dial. The control section 20 thenplays back the piece of selection content in accordance with a procedureof selection content playback process SRT1 (described below), andproceeds to step SP7.

The negative result at step SP4 means that the user performs the dialoperation at relatively high speed. This means that the control section20 should proceed to the high speed switch mode to keep playing thecurrently-played piece of music content SC. In this case, the controlsection 20 proceeds to next step SP6.

At step SP6, in a similar way to that of step SP5, the control section20 scrolls the thumbnail images SG on the display section 8 by one framein a direction corresponding to the rotation direction of the selectiondial. However, the control section 20 keeps playing the same piece ofmusic content SC, and then proceeds to nest step SP7.

At step SP7, the control section 20 updates the preceding rotation timeta such that the current time tp is set as the preceding rotation timeta for next dial operation. The control section 20 subsequently returnsto step SP2 to perform the series of processes.

(5) Playing Time of Piece of Content

(5-1) Basic Principle of Playing Piece of Content

By the way, in a case in which the piece of selection content SC isswitched to another in response to the user's dial operation of theselection dial 11, the control section 20 of the audio device 1 stopsplaying, when the dial operation is completed, the previously-selectedpiece of music content MC and starts playing the recently-selected pieceof selection content SC.

At this time, the control section 20 of the audio device 1 does notalways start from its top part when playing back the recently-selectedpiece of selection content SC. The control section 20 takes over theelapsed time of the previously-selected piece of selection content SCbeing played, or a point on a stream of the previously-selected piece ofselection content SC to which the control section 20 has played (thispoint will be also referred to as a “playback point”).

For example, as shown in FIGS. 9A and 9B, at time instance t10 when theuser performs the dial operation slowly, the control section 20 of theaudio device 1 starts playing the piece of content A from a point whereits playback elapsed time is tm10 as shown in FIG. 9C.

When the piece of selection content SC is switched, the control section20 of the audio device 1 stops the piece of content A at time instancet12, or at the playback elapsed time tm11 (FIG. 9C), and then startsplaying the piece of content B from a point where the playback elapsedtime is tm11 (FIG. 9D).

In a similar way, when the piece of selection content SC is switched,the control section 20 of the audio device 1 stops the piece of contentB at time instance t14, or at the playback elapsed time tm 12 (FIG. 9D),and then starts playing the piece of content C from a point where theplayback elapsed time is tm12 (FIG. 9E). When the piece of selectioncontent SC is switched, the control section 20 of the audio device 1stops the piece of content C at time instance t16, or at the playbackelapsed time tm 13 (FIG. 9E), and then starts playing the piece ofcontent D from a point where the playback elapsed time is tm13 (FIG.9E).

In this manner, as shown in FIG. 9G, the control section 20 of the audiodevice 1 sequentially plays the part of piece of content A which isbetween the playback elapsed time instances of t10 and t11, the part ofpiece of content B which is between the playback elapsed time instancesof t11 and t12, the part of piece of content C which is between theplayback elapsed time instances of t12 and t13, and the part of piece ofcontent D which is after the playback elapsed time instance t13. In thisway, the control section 20 takes over the playback elapsed time whenswitching what it plays back.

In a case in which the user performs the dial operation at relativelyhigh speed as shown in FIGS. 10A and 10B, the control section 20 of theaudio device 1 starts playing the piece of content A at time instancet20 from a point where the playback elapsed time is tm20 (FIG. 10C).When the piece of selection content SC is sequentially switched, thecontrol section 20 stops the piece of content A at time instance t24 ata point where the playback elapsed time is tm21 (FIG. 10C), and thenstarts playing the piece of content D from a point where the playbackelapsed time is tm21 (FIG. 10D).

In this manner, even if the user swiftly performs the dial operation,the control section 20 of the audio device 1, as shown in FIG. 10E,sequentially plays back the part of piece of content A which is betweenthe playback elapsed time instances of tm20 and tm21, and the part ofpiece of content D which is after the playback elapsed time tm21. Inthis way, the control section 20 takes over the playback elapsed timewhen switching what it plays back.

In this manner, each time the piece of selection content SC is switched,the control section 20 of the audio device 1 starts playing the piece ofselection content SC from various points. This allows the user to listento various points of the piece of selection content SC. This can befresh and enjoyable, compared to a device that always plays back thepiece of selection content SC from its top part.

By the way, when the total playing time Ts of the recently-selectedpiece of selection content SC is shorter than the playback elapsed timetm, the control section 20 of the audio device 1 utilizes the remainderon division of Ts (Total playing time) by tm (Playback elapsed time) asnew playback elapsed time tm. In this manner, in spite of whether thetotal playing time Ts of the piece of selection content SC is long orshort, the control section 20 can play back it from various parts.

In this manner, when the piece of selection content SC is switched bythe user's dial operation of the selection dial 11, the control section20 of the audio device 1 takes over the playback elapsed time of thepreviously-selected-and-played piece of music content MS, and thenstarts playing back the recently-selected piece of selection content SCfrom the same point as that of the previously-selected piece ofselection content SC.

(5-2) Procedure of Content Playback Process

With reference to FIG. 12, a procedure of selection content playbackprocess SRT1 will be described. The selection content playback processis executed when the control section 20 of the audio device 1 plays backthe newly-selected piece of selection content SC.

During the procedure of selection content switch process RT1 (FIG. 11),the control section 20 starts the procedure of selection contentplayback process SRT1 as subroutine, and then proceeds to step SP11. Atstep SP11, the control section 20 memorizes the playback elapsed time tmof the currently-played piece of selection content SC (or thepreviously-selected piece of selection content SC), and then proceeds tonext step SP12.

At step SP12, the control section 20 compares the total playing time Tsof the newly-selected piece of selection content SC with the playbackelapsed time tm, and then proceeds to next step SP13.

At step SP13, the control section 20 checks whether the total playingtime Ts is longer than the playback elapsed time tm. The affirmativeresult at step SP13 means that the recently-selected piece of selectioncontent SC can be played from the playback elapsed time tm. In thiscase, the control section 20 proceeds to next step SP15.

On the other hand, the negative result at step SP13 means that the totalplayback time Ts is shorter than the playback elapsed time tm. It meansthat the recently-selected piece of selection content SC can not beplayed from the playback elapsed time tm. In this case, the controlsection 20 proceeds to next step SP14.

At step SP14, the control section 20 sets the reminder on division ofthe playback elapsed time tm by the piece of selection content SC as newplayback elapsed time tm, and then proceeds to next step SP15.

At step SP15, the control section 20 starts playing therecently-selected piece of selection content SC form the playbackelapsed time tm, and then proceeds to next step SP16 to end theprocedure of content playback process SRT1. The control section 20subsequently returns to the procedure of selection content switchprocess RT1 (FIG. 11).

(6) Switch the Piece of Content to Be Played

By the way, when the different thumbnail image SG is selected by thefocus frame FC1 in response to the user's dial operation of theselection dial 11, as mentioned above, the control section 20 of theaudio device 1 scrolls the thumbnail images SG on the content displaysection 8 to the right or left in accordance with the rotation directionof the selection dial 11.

For example, when the thumbnail image SGA of the piece of content A issurrounded by the focus frame FC1 on the content display section 8 asshown in FIG. 13A (i.e. when the piece of content A is the piece ofselection content SC), the control section 20 of the audio device 1accepts the dial operation in which the user rotated the selection dial11 at its minimum angular increment to the right to move the thumbnailimages SG by one frame.

In this case, as shown in FIGS. 13B to 13D, the control section 20 ofthe audio device 1 keeps displaying the focus frame FC1 at the sameposition on the content display section 8. And then, in accordance withthe dial operation, the control section 20 gradually scrolls thethumbnail images SG (SGY, SGZ, SGA, SGB and SGC) to the left to movethem by one frame as shown in FIG. 13E. The control section 20 thenstops this movement when the thumbnail image SGB of the piece of contentB is surrounded by the focus frame FC1.

At this time, when the piece of selection content SC is switched inresponse to the dial operation, the control section 20 of the audiodevice 1 starts playing back the recently-selected piece of selectioncontent SC. At this time, the control section 20 gradually turns downthe volume of the previously-selected piece of selection content SC(fade-out), while the control section 20 gradually turns up the volumeof the recently-selected piece of selection content SC (fade-in).

Actually, the control section 20 of the audio device 1, as shown inFIGS. 14A and 14B, performs fade-out process to gradually turn down theplayback volume level of the piece of content A at both left and rightchannels from a usual level to zero. In addition, the control section 20performs fade-in process to gradually turn up the playback volume levelof the piece of content B from zero to a usual level.

In addition to that, the control section 20 of the audio device 1controls the volumes of the left and right channels separately. Thecontrol section 20 performs fade-in and fade-out processes on the leftand right channels at different timings. The playback volume level ofthe right channel changes earlier than that of the left channel by is(Timing difference).

As shown in FIGS. 14A and 14B, at time instance t31, the control section20 of the audio device 1 controls the left and right channels so thattheir playback volume levels become almost the same as for the piece ofcontent A (FIG. 15A). This gives the user a feeling that the sound imageof the piece of content A exists on almost the center (FIG. 15B).

At time instance t32, the control section 20 of the audio device 1 muchmore turns down the playback volume level of the right channel than thatof the left channel (FIG. 16A). This gives the user a feeling that thesound image of the piece of content A exists on the left side as shownin FIG. 16B.

After that, at the time instance t33 or the around, the control section20 of the audio device 1 gradually turns down the playback volume levelof the piece of content A on the left channel from a usual volume level,and also turns down the playback volume level of the piece of content Aon the right channel to zero. In addition, the control section 20gradually turns up the playback volume level of the piece of content Bfrom zero level.

At time instance t34, as shown in FIG. 17A, the control section 20 ofthe audio device 1 outputs the sound of the piece of content A on theleft channel at approximately middle playback volume level and the soundof the piece of content B on the right channel at approximately middleplayback volume level. This gives the user a feeling that as shown inFIG. 16B, the sound image of the piece of content A exists on the leftside and the sound image of the piece of content B exists on the rightside.

At time instance t35, the control section 20 of the audio device 1 turnsdown the playback volume level of the piece of content A on the leftchannel to zero and then gradually increases the playback volume levelof the piece of content B on the left channel from zero level. Inaddition, the control section 20 gradually turns up the playback volumelevel of the piece of content B on the right channel to a usual volumelevel.

At time instance t36, the control section 20 of the audio device 1, asshown in FIG. 18A, outputs the sound of the piece of content B on theleft channel at approximately middle playback volume level, and alsooutputs the sound of the piece of content B on the right channel at theusual volume level. That gives the user a feeling that the sound imageof the piece of content B exists on the right side as shown in FIG. 18B.

At time instance t37, as shown in FIG. 19A, to make the volumes of thepiece of content B on the left and right channels almost the same, thecontrol section 20 of the audio device 1 gives the user a feeling thatthe sound image of the piece of content B exists on almost the center asshown in FIG. 19B.

In this manner, as shown in FIGS. 14A and 14B, the control section 20 ofthe audio device 1 separately controls the volume levels of the left andright channels such that the volume level associated with theupstream-side (or right-side) thumbnail images SG being scrolled changests (ts: Timing difference) earlier than the other. Accordingly, as shownin FIGS. 15B to 19B, that gives the user the following feeling: thesound of the piece of content A is faded out and its sound imagegradually moves from the center from the left, while the sound of thepiece of content B is faded in and its sound image gradually moves tothe center from the right.

Accordingly, when what the focus frame FC1 selects is switched from onethumbnail image SG to another in accordance with the user's dialoperation of the selection dial 11 to the right, the control section 20of the audio device 1 can give the user the following feeling: the soundimages of the previously-selected and recently-selected pieces ofselection content SC flow from the right to left in association with themovement of the thumbnail image SG (the thumbnail image SGA which isassociated with the previously-selected piece of selection content SC,in this case) going out of the focus frame FC1 to the left and anotherthumbnail image SG (the thumbnail image SGB which is associated with therecently-selected piece of selection content SC, in this case) goinginto the focus frame FC1 from the right.

By the way, when the control section 20 of the audio device 1 acceptsthe user's dial operation of the selection dial 11 which is rotated tothe left, the control section 20 scrolls the thumbnail images SG fromthe left to the right. In addition, the control section 20 controls theleft- and right-sides volume levels in left-right reverse manner fromthe above method illustrated by FIGS. 14 to 19. This gives the user afeeling that the sound images of the previously- and recently-selectedpieces of selection content SC flow from the left to the right.

In this manner, the control section 20 of the audio device 1 scrolls, inaccordance with the user's dial operation of the selection dial 11, thethumbnail images SG on the content display section 8 to the right or theleft, and controls the left- and right-sides volume levels such that theone is faded in or out ts (ts: Timing difference) earlier than theother. That gives the user a feeling that the sound images of thepreviously- and recently-selected pieces of selection content SC flow tothe left or the right in accordance with the movement of the thumbnailimages SG.

(7) Operation and Effect

With the audio device 1 with the above configuration, when the userperforms the dial operation of the selection dial 11, the controlsection 20 of the audio device 1 switches what the focus frame FC1selects from one thumbnail image SG to another, and then plays back thenewly-selected piece of selection content SC.

In a case in which the dial operation is performed several times and theintervals of the operation are greater or equal to the waiting time tw,the control section 20 of the audio device 1 sequentially plays back therecently-selected pieces of selection content SC.

Accordingly, if the intervals of the dial operation are greater or equalto the waiting time tw, the control section 20 of the audio device 1proceeds to the low speed switch mode to let the user listen to thepieces of selection content SC one after another.

In this case, the user slowly performs the dial operation because he/shemay want to listen to each piece of selection content SC selected. Inline with his/her intention, the control section 20 of the audio device1 allows the user to listen to those pieces of selection content SC oneafter another while he/she performs the dial operation.

On the other hand, in a case in which the dial operation is performedseveral times and the intervals of the operation is less than thewaiting time tw, the control section 20 of the audio device 1 proceedsto the high speed switch mode where the control section 20 keeps playingthe same previously-selected piece of selection content SC. After thedial operation is completed, the control section 20 starts playing thefinally-selected piece of selection content SC.

In this case, when the intervals of the dial operation are less than thewaiting time tw, the control section 20 of the audio device 1 skips somepieces of selection content SC selected by the user, and let the userlisten to only the finally-selected piece of selection content SC.

In this manner, the control section 20 of the audio device 1 keepsplaying back the originally-selected piece of selection content MC untilthe dial operation is completed without playing back any pieces ofselection content SC selected halfway. This prevents the user fromfeeling discomfort, such as noise caused by the pieces of selectioncontent SC switched at short intervals.

Moreover, in this case, the user swiftly performs the dial operationbecause he/she wants to listen to only the finally-selected piece ofmusic content MC. In line with that, the control section 20 of the audiodevice 1 skips the pieces of selection content SC selected halfwayduring he/she performs the dial operation, and lets the user listen tothe finally-selected piece of selection content SC.

Furthermore, although the control section 20 of the audio device in thehigh speed switch mode does not change what it plays back until the dialoperation is completed, the control section 20 switches what the focusframe FC is selecting from one thumbnail image SG to another on thecontent display section 8 in accordance with the dial operation in realtime. This allows the user to recognize which piece of content(selection content SC) is selected in real time.

In this manner, the control section 20 of the audio device 1 proceeds,in accordance with the speed of the user's dial operation of theselection dial 11, to the low or high speed switch mode. Accordingly,this prevents the user from feeling discomfort while listening to thepieces of music content MC even if he/she wants to listen to each pieceof music content MC to check them or he/she wants to listen to onlyhis/her desired piece of music content MC without listening to others.

The control section 20 of the audio device 1 controls, when the piece ofmusic content MC to be played is switched, the playback volume level toperform fade-out and fade-in. This prevents radical changes in volume,and prevents the user from feeling discomfort.

In addition, the control section 20 of the audio device 1 performsfade-in and fade-out on the left and right channels such that the one ists (ts: Timing difference) earlier than the other. This gives the user afeeling that the sound images change according to the thumbnail imagesSG scrolled. This entertains the user.

The above configuration makes this possible: the control section 20 ofthe audio device 1 sequentially switches the piece of selection contentSC in response to the user's dial operation of the selection dial 11; ifthe intervals of the dial operation is less than the waiting time tw,the control section 20 keeps playing back the originally-selected pieceof selection content SC while he/she performs the dial operation: thecontrol section 20 then, when the dial operation is completed, stops theoriginally-selected one and plays back the finally-selected piece ofselection content SC. This prevents him/her from feeling discomfort tolisten to his/her desired piece of music content MC.

(8) Other Embodiment

In the above-noted embodiments, the audio device 1 keeps playing theoriginally-selected piece of selection content SC when the user swiftlyperforms the dial operation. However the present invention is notlimited to this. For example, the audio device 1 may turn down theplayback volume level of the pieces of selection content SC while theuser performs the dial operation, and put a confirmation sound, whichindicates that the dial operation has been accepted, on the sound of thepieces of selection content SC.

In addition, in the above-noted embodiments, when the piece of musiccontent MC to be played is switched to another, the audio device 1 getsthe previously-selected piece of music content MC faded out, and getsthe recently-selected piece of music content MC faded in. However thepresent invention is not limited to this. The audio device 1 may performcross-fade, or put the part of the previously-selected piece of musiccontent MC to be faded out on the part of the recently-selected piece ofmusic content MC to be faded in. Alternatively, the audio device 1 mayperform either fade-out or fade-in.

Moreover, in the above-noted embodiment, the audio device 1 controls theplayback volume levels of the pieces of music content MC on both theleft and right channels to give the user a feeling that the sound imagesof the pieces of music content MC changes according to the thumbnailimages SG scrolled. However the present invention is not limited tothis. For example, the audio device 1 may control the playback volumelevels of the pieces of music content MC on both the left and rightchannels to give the user a feeling that the sound images of the piecesof music content MC changes separately from the thumbnail images SGscrolled. Alternatively, the audio device 1 may make the playback volumelevels of the pieces of music content MC on both the left and rightchannels almost the same so that the sound images exist on almost thecenter. Alternatively, the audio device 1 may control the phase of thepieces of music content MC on both the left and right channels to changethe sound images.

Furthermore, in the above-noted embodiments, rotating the selection dial11 switches the piece of selection content SC. However the presentinvention is not limited to this. For example, pushing selectionbuttons, such as the operation buttons 9, may switch the piece ofselection content SC. Alternatively, putting and moving a finger on atouch panel on the audio device 1 may switch the piece of selectioncontent SC.

In this case, the number of times of pushing the selection buttonsduring a predetermined period may determine whether the audio device 1proceed to the low or high speed switch mode. For example, the audiodevice 1 may proceed to the high speed switch mode when the operationbutton is pushed more than the predetermined period of time.Alternatively, the speed of the finger on the touch panel may determinewhether to proceed to the low or high speed switch mode.

Furthermore, in the above-noted embodiments, the pieces of music contentMC are arranged in order of release date (year, month and day). Howeverthe present invention is not limited to this. The pieces of musiccontent MC may be arranged in various ways, such as in alphabeticalorder, in order of total playing time, or in order of storage.Alternatively, the pieces of music content MC may be arranged randomly.

In addition, the pieces of music content MC may be placed side by sidenot only in a row, but also in a lattice or random pattern. In thiscase, their thumbnail images SG may be selected by operation instructionmeans such as a mouse.

Furthermore, in the above-noted embodiments, the audio device 1, wherethe piece of music content MC to be played is switched in accordancewith the user's operation instruction, is applied. However the presentinvention is not limited to this. For example, a video recorder, wherethe pieces of video content are stored in a Hard Disk Drive and thepiece of video content to be played is switched in accordance with theuser's operation instructions, may be applied.

Furthermore, in the above-noted embodiments, the audio device 1 withhardware components is applied. However the present invention is notlimited to this. Electronic devices, such as personal computers andmobile phones capable of playing back music and displaying information,may perform a content playback program and other programs to switch whatit plays back from one piece of music content MC to another inaccordance with the user's operation instructions. In this case, theuser may operate keys or a mouse to switch the piece of music content MCto be played.

In addition, as a storage medium for storing the content playbackprogram and other programs, the following media may be applied to: theROM 20B of the control section 20, the Hard Disk Drive 22, an externalstorage media such as the optical disc 4 and the small memory card 6.The programs in the external storage media may be installed on the HardDisk Drive 22. The audio device 1 may acquire the content playbackprogram and other programs from outside through a communication cable(such as Universal Serial Bus (USB) cable and “Ethernet (RegisteredTrademark)”), or a wireless Local Area Network (LAN) (such as IEEE802.11a/b/g (IEEE: Institute of Electrical and Electronics Engineers)).

Furthermore, in the above-noted embodiments, the audio device 1, whichis equivalent to the content playback apparatus, includes: the imagedisplay section 26, which is equivalent to display means; the audioreproduction section 28, which is equivalent to playback means; theoperation input section 27 and the reproduction control section 20D,which are equivalent to switch means; and the reproduction controlsection 20D, which is equivalent to playback control means. However thepresent invention is not limited to this. The content playback apparatusmay include other circuit components which are equivalent to the displaymeans, the playback means, the switch means and the playback controlmeans.

The content playback apparatus, content playback method and storagemedium according to an embodiment of the present invention may be alsoapplied to various content playback devices capable of selecting andplaying a desired piece of content out of a plurality of pieces ofcontent.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed:
 1. A non-transitory storage medium storing an imageviewing program that, when executed, causes an image viewing apparatusto implement a method of: displaying a plurality of thumbnailscorresponding to a respective plurality of images; detecting a selectionof a thumbnail of the plurality of thumbnails; and displaying an imageof the plurality of images corresponding to the selected thumbnail,wherein if, while displaying a first image of the plurality of imagescorresponding to a first thumbnail of the plurality of thumbnails, aselection of a second thumbnail of the plurality of thumbnails isdetected, and a selection of a third thumbnail of the plurality ofthumbnails is subsequently detected within a predetermined period oftime after the selection of the second thumbnail is detected, continuingto display the first image, at least until the selection of the thirdthumbnail is detected, and if, while displaying the first image, theselection of the second thumbnail is detected, and a selection ofanother thumbnail of the plurality of thumbnails is not detected withinthe predetermined period of time after detecting the selection of thesecond thumbnail, ceasing display of the first image, and displaying asecond image of the plurality of images, the second image correspondingto the second thumbnail.
 2. The non-transitory storage medium of claim1, wherein the plurality of thumbnails are displayed side by side in arow.
 3. The non-transitory storage medium of claim 1, wherein theplurality of thumbnails are displayed along an axis in a chronologicalorder.
 4. The non-transitory storage medium of claim 3, wherein the axisis horizontal and the chronological order is based on a plurality ofdates and times associated with the plurality of thumbnails.
 5. Thenon-transitory storage medium of claim 1, wherein the selection of thethumbnail is detected in accordance with a user's touch.